The concentrator has a code designation of RT-L-RT:C (R-refracting section of a component lens, T-transmitting section of a component lens, L-reflecting section of a component lens, C-concentrating stage lens).
Prior art includes the following patents:
Biconical Refractor, U.S. Pat. No. 2,881,654, 4/14/59, D. S. Toffolo. This is a beam concentrator with an upper component lens which receives an annular incipient beam and is therefore only 60% effective.
Conical Refractor, U.S. Pat. No. 2,882,784, 4/14/59, D. S. Toffolo. This also is a beam concentrator with an upper component lens which receives an annular incipient beam.
Conical Split-Image Microscopic Lens, U.S. Pat. No. 4,277,148, 7/7/81, by this inventor. This is a stage lens with three component lenses which receive a whole incident beam and emit a whole enlarged beam.
Reflective Beam Concentrator, U.S. Pat. No. 4,325,612, 4/20/82, by this inventor. This is a beam concentrator which has a lower component lens identical to the lower component lens of the subject disclosure.
Conical Beam Concentrator, U.S. Pat. No. 4,333,713, 6/8/82, by this inventor. This is a beam concentrator which has a lower component lens identical to that of the subject disclosure.